Ethnographic Arms & Armour - View Single Post - Metal De-Corroder and its effects

Atlantia · 16th September 2010, 06:50 PM

Hi,

Sounds like your rust eater is a somewhat acidic product. This is not umcommon of course, and most rust removers are by nature highly corrosive.
The results on the sword blade looks quite good in the pictures.
The results on the gun parts are perhaps not quite as desirable.
Thing is, oxidisation goes through several stages, and having some stable oxidisation in pits is sometimes more desirable than 'cleaning' those pits out.
On an old steel/iron surface, what can look like a mottled dark shiny 'patina' (not rusty and flaky just dark and obviously slightly oxidised), will often be hiding a multitude of small, tiny and microscopic corroded imperfections which will all be revealed if using a corrosive solution to eat the oxidisation out of them.
even an undamaged polished steel surface can be affected by the acid and mildly etched. Which can leave a grey looking colour.
Of course it all depends on the type of steel/iron, how its treated with the etching solution etc.
Try some tests with scrap pieces of ferrous metals.

One thing to remember is that there is no 'magic bullet' for cleaning up a neglected piece of rusty metal.
Slow is best, as removing patina is much easier than restoring it.
If a piece is pitted, then a decision has to be made as to if the oxidisation is to be totally removed, stabilised, left alone, repolished etc, etc.
Total removal might make a piece look 'sandblasted', repolishing might make it look new.....
The two 'best' solutions are often:
Stabilise and conserve, removing loose flakes but essentially leave 'as is'.
Or partial removal of oxidisation (down to or close to the level of the surface) while preserving the dark stable oxidisation in the small pits so as to maintain a 'natural' flat shiny surface (even if it is mottled).
So perhaps a wipe over with your solution to start to remove the loose, surface stuff, then neutralise and repeat if needed.
Never a good idea to treat a piece with different techniques in sections as you might get very different results. Or worse, you might get 'rings' where the top of the liquid level was.

16th September 2010, 06:50 PM	#3
Atlantia Member Join Date: Jun 2008 Location: The Sharp end Posts: 2,928	Hi, Sounds like your rust eater is a somewhat acidic product. This is not umcommon of course, and most rust removers are by nature highly corrosive. The results on the sword blade looks quite good in the pictures. The results on the gun parts are perhaps not quite as desirable. Thing is, oxidisation goes through several stages, and having some stable oxidisation in pits is sometimes more desirable than 'cleaning' those pits out. On an old steel/iron surface, what can look like a mottled dark shiny 'patina' (not rusty and flaky just dark and obviously slightly oxidised), will often be hiding a multitude of small, tiny and microscopic corroded imperfections which will all be revealed if using a corrosive solution to eat the oxidisation out of them. even an undamaged polished steel surface can be affected by the acid and mildly etched. Which can leave a grey looking colour. Of course it all depends on the type of steel/iron, how its treated with the etching solution etc. Try some tests with scrap pieces of ferrous metals. One thing to remember is that there is no 'magic bullet' for cleaning up a neglected piece of rusty metal. Slow is best, as removing patina is much easier than restoring it. If a piece is pitted, then a decision has to be made as to if the oxidisation is to be totally removed, stabilised, left alone, repolished etc, etc. Total removal might make a piece look 'sandblasted', repolishing might make it look new..... The two 'best' solutions are often: Stabilise and conserve, removing loose flakes but essentially leave 'as is'. Or partial removal of oxidisation (down to or close to the level of the surface) while preserving the dark stable oxidisation in the small pits so as to maintain a 'natural' flat shiny surface (even if it is mottled). So perhaps a wipe over with your solution to start to remove the loose, surface stuff, then neutralise and repeat if needed. Never a good idea to treat a piece with different techniques in sections as you might get very different results. Or worse, you might get 'rings' where the top of the liquid level was.